Adjustable, self-cleaning rotary machine which is intended to produce a flow of purefied fluid

ABSTRACT

The invention relates to a rotary machine comprising a rotor ( 6 ) bearing a packing ( 9 ) in the form of a ring which is at least partially made from a flexible, fluid-permeable material. The inventive machine also comprises variable-speed drive means for rotating the rotor ( 6 ) and means which enable the aforementioned packing ( 9 ) to be deformed in response to a variation in the rotational speed of the rotor ( 6 ). As a result, the machine can produce an air flow, extract material contained in said flow and perform a self-cleaning cycle.

The present invention relates to a rotary machine capable of generatingthe flow of a fluid flux, while simultaneously treating it by extractingmaterials contained in this flux and capable of releasing the retainedmaterials during a self-cleaning process and the filtration performancesof which may be adapted to variable needs very easily.

For example, it is applied to ventilation and purification (pollutioncontrol) of ambient air or exhaust gases of heat engines or to theseparation of material transported by liquid effluents.

Generally, it is known that to generate an air flux at a pressure closeto atmospheric pressure, fans (or suction devices) are notably used,which comprise a rotor driven by a motor and provided with blades orwith a turbine which imparts to the fluid an increase in velocity on theone hand and, a diffuser on the other hand, which has the function ofconverting part of the kinetic energy into a further increase inpressure.

In spite of multiple expended efforts to reduce the noise, it is foundthat the presently proposed fans comprising centrifugal fans, remainnoisy at medium or high rotational velocities. This is both due to thefact that the blades in a stiff material are the site of vibrationsnotably resulting from the presence of eccentric masses in the rotor,and/or from the action of the fluid on the blades and/or the turbulencesgenerated by the blades.

Moreover, these fans are not able to provide by themselves apurification function for the transported fluid: to fulfill such afunction, they are necessarily associated with purification devices suchas filters in which the impurities are retained. Such is the case forhome vacuum cleaners which comprise a chamber for filtering dusts in thesuction circuit of the turbine.

The applicant has already proposed a rotary machine, the rotor of whichcomprises at least one fitting made in a material permeable to fluids,capable of driving the fluid into rotation which it contains so as toprovide its ejection under the effect of the centrifugal force; thefitting according to a preferred embodiment consists of materialconsisting of looped fibers, the diameter of which is of the order of0.1 to 5 mm; the aforesaid fitting is permanently attached to a disk orto a cage, rotatably mounted in a casing, and driven by a motor; thefluid is sucked through a circular port, not necessary coaxial, and isthen delivered into the annular space partly surrounding the disksupporting the fitting, and flows in the direction of the dischargenozzle located at the end of said annular space.

Generally, it is known that the filtration efficiency of rotary machinessuch as the one described above, is defined as the % ratio of thedeviation between the ambient particle concentration and the particleconcentration at the output of these rotary machines, reduced to theambient concentration, multiplied by 100.

Moreover, the aeraulic efficiency of these rotary machines isproportional to the ratio of the product of the pressure and of the flowrate of the fluid at the discharged nozzle, reduced to the mechanicalpower supplied to the rotor.

For given geometrical and physical characteristics of their fitting, thefiltration efficiency of machines of the aforesaid type, changeaccording to the rotational velocity of the fitting and to the size ofthe particles transported by the fluid.

When the rotational velocity of the fitting increases, the filtrationefficiency increases for large particles (impact collection), whereasthe filtration efficiency is reduced for small particles (fluxentrainment effect).

When the rotational velocity of the fitting becomes very high, thefiltration efficiency becomes negative for the small trapped particlesfollowing a release effect of said small particles; the same releaseeffect occurs for the large trapped particles, at a low rotationalvelocity of the fitting or during stops and restarts.

As for the aeraulic efficiency, it increases with the rotationalvelocity of the fitting and then decreases beyond an optimum.

As a conclusion, for given geometrical and physical characteristics of afitting, at a rotational velocity considered as optimum, therecorresponds a maximum filtration efficiency for a given particlespectrum and it should correspond to a maximum aeraulic efficiency.

Now, it is found that it is not easy to obtain maximum filtrationefficiency for the widest possible particle spectrum at a givenrotational velocity, and this is all the less easy if, at this samerotational velocity, there should correspond a maximum aeraulicefficiency.

Moreover, clogging of the cavities of the fitting increases filtrationefficiency to the detriment of the aeraulic efficiency, and there is amedium term risk of making the rotary machine inoperative; replacementof the fitting becomes essential.

The object of the invention is therefore to solve these difficulties byutilizing changes in the physical characteristics of the fitting (andconsequently the change in the filtration efficiency), the aeraulicefficiency and the capacity of discharging trapped particles generatedby variations of its rotational velocity.

It proposes the making of a sucking/discharging/operationally adjustablerotary machine with a very simple and not very costly design, whichfurther is very silent, while providing by itself a treatment of thegenerated fluid flux, and capable of retaining or releasing at will thetransported materials, during a self-cleaning process.

For this purpose, the rotary machine according to the inventioncomprises a rotor bearing a fitting in the form of a crown at leastpartly made in a flexible material, permeable to fluids, means fordriving the rotor into rotation at a variable velocity, and meansallowing for carrying out a deformation of the fitting in response tothe variation of the rotating speed of the rotor.

Advantageously, the means for carrying out the aforesaid deformationinvolve a transmission device between the rotor and one of thecylindrical faces of the fitting, so that a change in the velocity ofthe rotor generates, under the effect of the change in the centrifugalforce which results therefrom, compression and/or expansion of thefitting which is retained by the transmission means.

As an alternative, these means may involve a transmission deviceconnecting the rotor to one of the two radial faces of the fitting, aswell as an annular part permanently attached to the other radial face ofthe fitting, so that due to the inertia of this annular part, a changein the rotational velocity of the rotor generates a process of torsionand compression of the fitting (compression due to bringing both radialfaces of the fitting together).

Of course, in one case as in the other, the fitting should be made in asufficiently flexible permeable material so that by adjusting therotational velocity, it is possible to obtain in steady flow conditionsthe desired filtration characteristics allowing particles in the desireddimensional range to be collected and, by varying the rotationalvelocity of the rotor, to obtain discharge of the previously collectedparticles and regeneration of the filtration characteristics.

Both of these solutions are particularly well suited to collectingmixtures of mists. For this purpose, the fitting may be made in anadsorbing material while means will be provided for spraying a liquidinto the sucked air flux. Means will further be provided for collectingthe liquid absorbed by the fitting and for ejecting it under the effectof the centrifugal force.

Embodiments of the invention will be described hereafter, asnon-limiting examples, with reference to the appended drawings wherein:

FIG. 1 is a schematic axial sectional view of a rotary machine fortreating a gas such as ambient air;

FIG. 2 is a transverse sectional view of the machine illustrated in FIG.1;

FIG. 3 is schematic axial sectional view of a first embodiment of therotary machine for treating gases;

FIG. 4 is a transverse sectional view of the rotary machine illustratedin FIG. 3;

FIGS. 5 a, 5 b, 5 c are a schematic illustration of a possible form ofrotor in a flexible material permeable to fluids;

FIGS. 6 a-6 c are axial sectional views of a second embodiment of therotary machine, in steady flow conditions, at a first rotationalvelocity (FIG. 6 a), at a second rotational velocity (FIG. 6 b) and intransient flow conditions during a sudden change in velocity (FIG. 6 c).

In the example illustrated in FIGS. 1 and 2, the rotary treatmentmachine comprises a casing 1 comprising two coaxial parallel rectangularflanges 2, 3, connected to each other by a slightly helical transversewall 4 which extends perpendicularly or obliquely relatively to bothflanges. This wall 4 opens up outwards, through a side port 5.Optionally, it may have a concave, convex profile or one tiltedrelatively to the axis of rotation. Inside the casing, a rotor 6 isrotatably mounted with an axis perpendicular to both flanges 2, 3, anddriven into rotation by an electric motor 7 permanently attached to theflange 3. This rotor is therefore at least partly encircled by thetransverse wall 4.

In this example, the rotor 6 comprises a cage 8 in which a crown 9permeable to air is contained. This crown 9 may be made in a flexible,reticular, and/or cellular material with open cells and/or in a fibrousor microfibrous material of natural origin, and/or a metal material,and/or a synthetic, hydrophilic and/or hydrophobic, oleophilic and/oroleophobic material, and/or coated with an adhesive substance.

The thickness of the cage 8 is substantially equal to the gap betweenboth flanges 2, 3.

The flange 2 comprises at right angles to the cavity delimited by thecrown, a circular port, not necessarily coaxial.

This port is extended with a tubular component 10 forming a suctionnozzle.

The operation of this rotary machine is then as follows: the driving ofthe crown 9 into rotation by the motor 7 causes the air contained inthis crown 9 to rotate. Under the effect of this rotation, the air masssubject to the centrifugal force flows into the space E between thecrown 9 and the transverse partition 4 where it is guided towards theoutput port 5. In the same way, this flow causes air in the cavity C andin the nozzle 10 to be sucked and therefore generates a suction current.

Upon putting the crown 9 into rotation, the cells forming the materialof the aforesaid crown 9, under the effect of the centrifugal force,stretch out in the area close to the axis of rotation, and arecompressed in the peripheral area, close to the cage 8. Thus, a gradientof filtration characteristics is formed radially, allowing a largeparticle or mist spectrum or bubbles (liquid phase operation) to becollected for example. Thus, at the high rotational velocities of thecrown 9, thereby promoting aeraulic efficiency, the filtrationefficiency is increased peripherally, for particles of small dimensions,and retained for particles of large dimensions, at the internal faceand/or in the bulk of the crown.

The air which flows out through port 5 is thereby purified.

Upon reducing the rotational velocity of the crown 9, below the ratedrotational velocity, the cells forming the material of the aforesaidcrown 9 resume their initial dimensions at a slow or zero rotationalvelocity, and notably those cells located in the periphery area, closeto the cage 8. Thus, the particles trapped in said cells may escapethrough port E; the cleaning process is thereby applied, with a devicefor diverting the flux loaded with particles, as illustrated in FIGS. 1and 2.

In the example illustrated in FIGS. 3 and 4, the treatment rotarymachine comprises a casing 1 comprising two coaxial parallel rectangularflanges 2, 3, connected to each other by a slightly helical transversewall 4 which extends perpendicularly or obliquely relatively to bothflanges. This wall 4 opens up outwards, through a side port 5.Optionally, it may have a concave convex profile or one tiltedrelatively to the axis of rotation. Inside the casing 1, a rotor 6 withan axis perpendicular to both flanges 2, 3 is rotatably mounted anddriven into rotation by an electric motor 7 permanently attached to theflange 3, this rotor is therefore at least partly encircled by thetransverse wall 4.

Advantageously, the transverse wall 4 is provided with flutes directeddownwards or with optionally helical or oblique relief features, eitherhydrophilic or hydrophobic, used for channelling the liquid in thedesired direction.

In this example, the rotor 6 comprises a crown 8 in which a crown 9permeable to air is located. This crown 9 may be made in a flexible,reticular and/or cellular material with open cells, and/or in a fibrousor microfibrous material of natural origin, and/or a metal and/orsynthetic material and/or having antiseptic properties. Advantageously,it may have adsorption or catalytic properties.

The thickness of the crown 9+cage 8 assembly is substantially equal tothe gap between both flanges 2, 3.

The flange 2 comprises, at right angles of the cavity delimited by thecrown, a circular port not necessarily coaxial.

This port is extended by a tubular component 10 forming a suctionnozzle.

This suction nozzle is fitted out with at least one head 11 for sprayinga liquid such as water or oil.

The lower flange 3 further comprises a basin 13 with a small width whichsubstantially extends along the transverse wall 4. One or more water (oroil) discharge ducts open into the bottom of this basin.

The operation of this rotary machine is then as follows: the driving ofthe crown 9 into rotation by the motor 7 causes the air contained inthis crown 9 to rotate and the latter to deform. Under the effect ofthis rotation, the mass of air subject to the centrifugal force, flowsinto the space E between the crown 9 and the transverse wall 4 where itis guided towards the output port 5. In the same way, this flow causesair to be sucked into the cavity C and into the nozzle 10 and thereforegenerates a suction current. This suction current receives a mist ofdroplets coming from the sprayer 11. This mist generates a first phasefor adsorbing impurities contained in the air.

During their passage in the crown 9, the droplets, loaded withimpurities are adsorbed by the flexible material, permeable to fluids,while the air continues to be ejected outwards. These droplets, whichare then channeled by the flexible (adsorbing) material, are thenthemselves also subject both to the centrifugal force and to gravity.They merge by coalescence along the fibers or on the walls of the cells,which generates their desorption. The resulting water (or oil) isejected onto the transverse wall and flows along the aforesaid flutes orthe aforesaid relief features in order to reach the basin 13 beforebeing discharged through the ducts 14.

Upon putting the crown 9 into rotation, the walls of the cells, or thefibers, or the microfibers, forming the material of the aforesaid crown9, under the effect of the centrifugal force, stretch out in the areaclose to the axis of rotation, and contract in the central area closethe cage 8. Thus, the radii of curvature of the microfibers of theperipheral area decrease, which causes an increase of the wettabilitycoefficient. A gradient of the filtration characteristics is formedradially, with progressive increase in the density of the network of thematerial, allowing a wide particle spectrum to be collected. Moreover,at the high rotational velocities of the crown 9 which thereby increasethe aeraulic efficiency, the filtration efficiency is increased forparticles of small dimensions and retained for particles of largedimensions.

The air which flows out through port 5 is thereby purified.

Upon reducing the rotational velocity of the crown 9, below the ratedrotational velocity, the cells or the microfibers forming the materialof the aforesaid crown 9 resume their initial dimensions at a slow orzero rotational velocity, and notably those located in the peripheralarea, close to cage 8. Thus, the particles trapped in said cells will beable to escape through port E; the cleaning process is thereby appliedwith a device for diverting the flux loaded with particles, asillustrated in FIGS. 3 and 4.

Of course, the invention is not limited to the embodiments describedearlier.

Thus, the fitting may have a composite structure. It may comprise twoportions more or less permeable or impermeable to the displaced orpropelled fluid, so as to direct the fluid into the mass or to increasethe collection and/or aeraulic efficiency of the reticular mass or todischarge condensates, liquids, or bubbles (in a liquid phase). Inparticular, the crowns may consist of superimposed and/or concentriclayers of different materials.

In the example illustrated in FIGS. 5 a, 5 b, 5 c, the crown 9 consistsof two concentric layers, located on either side of the cage 8.

The internal crown 9 a is of the same nature of the one shown in theearlier examples; the external crown 9 b consists of a material havinglarger cells than the one characterizing the material of the crown 9 a;moreover, its radial thickness is larger than the one defining theinternal crown 9 a.

Upon putting crowns 9 a and 9 b (FIG. 5 a) into rotation, the cellsforming the material of the aforesaid crown 9 a, under the effect of thecentrifugal force, expand in an area close to the axis of rotation andcontract in the peripheral area, close to the cage 8. The cells formingthe material of the aforesaid crown 9 b, under the effect of thecentrifugal force, increasingly expand outwards. Thus, a gradient offiltration characteristics is formed radially by the crowns 9 a and 9 ballowing a very wide particle spectrum to be collected.

The air which flows out through port 5 is thereby purified.

Upon reducing the rotational velocity of the crowns 9 a and 9 b, belowthe rated rotational velocity (FIG. 5 b), the cells forming the materialof the aforesaid crowns 9 a and 9 b, resume their initial dimensions atzero rotational velocity, and notably those located in the peripheralarea concerning the crown 9 b. Thus, the particles, notably of largedimensions, trapped in said cells, may escape through port E.

Upon increasing the rotational velocity of the crowns 9 a and 9 b,beyond the rated rational velocity (FIG. 5 c), the cells forming thematerial of the crown 9 a will be compressed, whereas those of the crown9 b will stretch. Thus, the particles, notably of small dimensions,trapped in said cells, will be able to escape through port E.

The cleaning process is thereby applied by the compression anddepression effect of crowns 9 a and 9 b at rotational velocities locatedon either side of the operating rated velocity by outward migration ofthe material retained by the crowns 9 a and 9 b.

This cleaning process is associated with a device for diverting the fluxloaded with particles, not illustrated in FIGS. 5 a, 5 b, 5 c.

Of course, the applications of the machines described above, may be verydiverse: pump, vacuum cleaner, circulator, fan, blower, hair dryer,phases separator, . . .

In all these applications, with the rotary machine according to theinvention, important simplifications may be provided and costs may bereduced. Taking into account the nature of the rotor (flexibility of thefitting), there is no risk to the user (as opposed to a conventionalrotor with blades). Moreover, in order to avoid clogging of thefittings, a method consisting of rapidly varying the rotational velocityof the rotor allows the retained material to be released.

In the illustrated example in FIGS. 6 a-6 c, the rotary machine has astructure similar to that of the embodiment of FIGS. 1 and 2.

Indeed, it comprises a casing 21 comprising two coaxial rectangularflanges 22, 23, connected to each other by a slightly helical transversewall 24 which extends perpendicularly or obliquely relative to bothflanges 22, 23.

Inside the casing 21, a rotor R, with an axis perpendicular to bothflanges 22, 23, is rotatably mounted and driven into rotation by anelectric motor 27 permanently attached to the flange 23. This rotor R istherefore at least partly encircled by the transverse wall 24.

The rotor R comprises a central axis 28 which extends coaxially to thecasing 21 and which is driven into rotation by the motor 27. This axis28 itself drives in its upper portion a disk 29, having an aperturedcentral portion 30. On this disk 29 is attached a fitting in the form ofa crown 31, made in a flexible material, permeable to fluids, theattachment between the disk 29 and the fitting 31 being exclusivelycarried out at the external edge 32 of the radial faces of both of thesecomponents.

The fitting in the form of a crown 31 is made in a flexible material,for example with a reticular and/or cellular structure with open cells.

The external edge 33 of the lower face of the fitting 31 is connected toa massive annular part 34, optionally rotatably mounted with thepossibility of axial displacement on the central axis 28 by means of abearing 35.

The operation of this machine is then as follows: under steady stateconditions (FIG. 6 a), the motor 27 rotates at constant velocity. Thisrotation generates a flow of air through the fitting 31 and accordinglya process for filtering the thereby produced air current. Thecentrifugal force which is exerted on the fitting 31 causes acompression of the reticular of cellular material which determines therange of sizes of the particles which will be retained by this material.

Accordingly, the operator may adjust this rotational velocity accordingto the sizes of particles, for which filtration is desired (FIG. 6 b).

Periodically, the fitting 31 may be cleaned so as to retain thefiltration efficiency. For this purpose, it will be sufficient to causea sudden change in the rotational velocity of the motor 27.

Indeed, this change has the effect of causing an angular shift betweenthe driving disk 30 of the fitting 31 and the annular part 34 whichbecause of its inertia exerts a resisting torque.

This angular shift causes torsion of the fitting 31 and a reduction inthe distance between the disk 29 and the annular part 34 (FIG. 6 c). Adual torsion/compression effect is obtained (like the one which isexerted on a floor cloth to extract the washing liquid) withadditionally a flow of air through the fitting.

This dual portion/compression effect may be repeated by carrying outseveral successive changes in velocity, while providing between eachchange in velocity sufficient time to allow the fitting 31 to resume itsinitial position. A particularly efficient cleaning of the fitting 31 isthereby obtained.

Optionally, the central axis 28 may comprise a helical groove(threading) cooperating with a finger (or internal screw thread)provided in the bearing 35.

In this case, a change in velocity according to whether this is anincrease or a decrease in the velocity may cause the disk 29 and theannular part 34 to be moved away from each other or to be brought closerto each other, and consequently an extension or a compression of thefitting 31.

According to another alternative embodiment of the invention, during thecleaning phases, the annular part 34 may be subject to vibrations, forexample axial vibrations, by the action of a tooth 36 permanentlyattached to the bearing 35 pressing against a notched or corrugatedannular surface 37 permanently attached to the casing 21 (FIG. 6 c).

Controllable braking means may also be provided for braking the rotationof the annular part 34 and thereby increasing the torsion/compressioneffect.

Also, a compression spring RE may be interposed between the aperturedcentral portion 30 and the annular part 34 or the bearing 35.

1-18. (canceled)
 19. A rotary machine capable of generating a flux offluid, comprising a rotor bearing a fitting in the form of a crown atleast partly made in a flexible material, permeable to fluids, means fordriving the rotor into rotation at a variable velocity, said machinecomprising self-cleaning means comprising as a combination: controlmeans capable of acting on the aforesaid means for driving the rotorinto rotation at a variable velocity so as to generate a sudden changein the rotational velocity of said rotor, coupling means between a firstface of the fitting and the aforesaid driving means, and an annular partborne by a second face of the fitting so that due to the inertia of thisannular part, said sudden change in the rotational velocity of saidrotor generates a process of torsion and/or compression of the fittingand consequently said self-cleaning of this fitting.
 20. The machineaccording to claim 19, wherein the aforesaid fitting has the form of acrown contained in a cage.
 21. The machine according to claim 19,wherein the aforesaid fitting has the form of a crown encircling a cage.22. The machine according to claim 19, wherein the aforesaid fittingcomprises two crowns, respectively contained in the aforesaid cage andencircling the aforesaid cage.
 23. The machine according to claim 19,wherein the aforesaid annular part is rotatably mounted with thepossibility of axial displacement on the axis for driving the rotor, bymeans of a bearing.
 24. The machine according to claim 23, wherein theaxis comprises a helical groove or threading cooperating with a fingeror internal screw thread provided in the bearing.
 25. The machineaccording to claim 23, comprising means for subjecting the annular partto vibrations.
 26. The machine according to claim 23, comprising itcomprises means for braking the annular part.
 27. The machine accordingto claim 19, wherein the aforesaid fitting is made in a flexible,reticular and/or cellular material with open cells.
 28. The machineaccording to claim 19, wherein the aforesaid fitting is made in aflexible fibrous or microfibrous material of natural origin and/or ametal and/or synthetic and/or antiseptic material.
 29. The machine forextracting impurities contained in a gas according to claim 19, whereinthe aforesaid fitting is made in an adsorbing material and in that itfurther comprises a device for spraying a liquid into the air fluxsucked up by the fitting on the one hand and means for collecting theliquid adsorbed by said fitting and ejected under the effect of thecentrifugal force on the other hand.
 30. The machine according to claim29, wherein the aforesaid fitting rotates between two parallel flangesand in that the lower flange is provided with a basin into which atleast one fluid discharge port opens.
 31. The machine according to anyof claims 29, wherein said flanges are connected together by atransverse wall which is provided with flutes directed downwards orrelief features optionally helical or oblique used for channeling theliquid in a desired direction.
 32. The machine according to claim 19,wherein a spring is interposed between both radial faces of the fitting.33. The machine according to claim 19, wherein the aforesaid fitting hasa composite structure comprising two portions more or less permeable orimpermeable to the displaced or propelled fluid, so as to direct thefluid into the mass or to increase the collection and/or aeraulicefficiency of the reticular mass or to discharge condensates, liquids orbubbles (in the liquid phase).
 34. The machine according to claim 19,wherein the aforesaid fitting comprises superimposed and/or concentriclayers of different materials.